Scientists have known for decades
that poverty leads to higher rates of illness and mortality. More recent UCSF research has
shown that these effects dont end at the poverty line. In fact, health improves at
each step of the social ladder.

"It is not simply the effects of income or education that are linked to better
health, but also the perception that one is higher on the social hierarchy," said
Nancy Adler, PhD, UCSF professor of psychiatry and lead author of the study which appears
in the November issue of Health Psychology, a journal published by the American
Psychological Association (APA).

The researchers found that women who placed themselves higher on the social ladder
reported better physical health, took less time to fall asleep at night and had lower
resting heart rates and less abdominal fat (a key indicator that these women adapt to
stress better), said Adler.

Perceptions of lower social standing were also associated with negative psychological
factors, including greater chronic stress, pessimism and lower perceived control of life.

The researchers studied a sample of 157 healthy white women age 30-46. In addition to
reporting on their income and education, the women completed a new survey that asked them
to rate their own socioeconomic status (SES). They were shown a drawing of a ladder with
ten rungs and told to think of the ladder as representing where people stand in society.
At the top of the ladder are people who are best off  those who have the most money,
education, and best jobs. At the bottom are people who are the worst off  who have
the least money, least education and worst jobs. Participants were then asked to place an
"X" on the rung which best represented where they think they stood on the
ladder.

The women, who had varying socio-economic backgrounds, were evaluated for psychological
indicators, including negative affectivity (how much they generally tend to feel negative
emotions), pessimism, perceived control over life, coping style, self-defined stress
levels, and chronic stress levels. Participants were also evaluated for sleep patterns,
resting physiological response, and fat distribution. A sub-sample of 59 women took part
in a laboratory stress study that examined their cortisol response to stress over a
three-day period.

Cortisol is a stress hormone that may play a role in the accumulation of abdominal fat,
explained Adler. Abdominal fat deposit, in turn, is linked to metabolic and cardiovascular
disease. "With repeated experiences of the stress, the body has greater exposure to
cortisol. Abdominal fat has a relatively greater sensitivity to cortisol than peripheral
fat, so individuals with higher cortisol reactivity, high resting levels of cortisol and
/or great exposure to events that evoke a stress response, accumulate greater abdominal
fat," she said. Researchers analyzed the accumulation of body fat by measuring body
mass index (BMI) and waist-to-hip ratios. They found that women who consistently secreted
cortisol when exposed to repeated stress had the lowest ladder ratings.

"Our findings suggest that perceived low SES is linked to greater stress. Low
subjective SES may either increase stress directly or make women more vulnerable to the
effects of stress," said Adler. She explained that lower ladder rankings are linked
to increased stress even when researchers controlled for a womans actual
socioeconomic placement (determined by education, occupation, income) and how much these
women report experiencing negative emotions.

The research serves as a human analog to studies of social ordering and health among
animals, explained Adler. Subordinate primates have higher cortisol, higher blood
pressure, and worse health than dominant animals in stable social environments, according
to previous research. "The ladder rankings may reflect direct social comparisons of
social rank that are more similar to dominance hierarchies than are traditional measures
of SES that include education, occupation, income," she said.

The fact that all participants were healthy, white women who had at least a high school
degree presents a limitation to the study, according to the researchers. In a second and
related paper, published in the same issue of Health Psychology, researchers determined
that subjective status may be a more important determinant of self-rated health for women
who have higher income levels  in this case whites and Chinese-Americans. For
Latinas and African Americans, who had lower average incomes and education levels,
household income was the most important determinant of how these women rated their health.

Coinvestigators on the first study included Elissa Epel, PhD, post-doctoral
fellow in the UCSF department of psychiatry; Grace Castellazzo, BSN, research nurse at
Yale University; and Jeannette Ickovics, PhD, associate professor of epidemiology and
public health at Yale University. The lead author on the second study was Joan Ostrove,
PhD, assistant professor of psychology at Macalester College. Co-investigators included
Adler, Miriam Kuppermann, PhD, MPH, UCSF assistant professor of obstetrics and gynecology;
and A. Eugene Washington, MD, UCSF professor and chair of obstetrics, gynecology.